A newly published study on the effects of climate change on marine biodiversity suggests global warming will cause a large chunk of the fish population to disappear from the tropics about 35 years from now.
Using the same climate change scenarios utilized by the United Nations' Intergovernmental Panel on Climate Change (IPCC) to project the massive-scale movement of marine life, UBC Fisheries Centre associate professor William Cheung and Miranda Jones, from the United Nations Environment Programme World Conservation Monitoring Centre, found that fish could move away from their present habitat at a rate of 15 kilometers per decade if the Earth's oceans get warmer by one degree Celsius by 2100.
The movement could be much faster though if the ocean water becomes hotter by three degrees Celsius: the fish could move away from their habitat at 26 kilometers per decade.
The researchers particularly looked at over 800 species of fish and invertebrates which include those that are often harvested for food such as tuna, cod, herring and halibut, and concluded that the warming climate will drive more fish particularly those from the tropical seas in Southeast Asia to cooler habitats such as the Arctic and Antarctic waters.
"Results indicate an average poleward latitudinal shift across species and Species distribution models (SDMs) at a rate of 15.5 and 25.6 km decade-1 for a low and high emissions climate change scenario, respectively," the researchers wrote in the Oct. 10 issue of the ICES Journal of Marine Science. "Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator."
Although the movement of the fish could open new opportunities for fisheries in the cooler regions, it could also affect the species that already live there as more fish population means increased competition for resources.
It isn't yet clear how the new species of fish will interact with the already existing population of fishes in the area. The situation could also cause fisheries management problems in affected countries as fish stocks cross different jurisdictions, the researchers said.
People who live in the tropics will feel most of the negative impact of fish migration towards the South and North Poles because they largely depend on marine resources.
"The tropics will be the overall losers," Cheung said. "This area has a high dependence on fish for food, diet and nutrition. We'll see a loss of fish populations that are important to the fisheries and communities in these regions."
